Outdoor Power Equipment and Small Engines - Question on throttle adjustment for 5 hp B&S carb

I’m stumped. Been working on a B&S 5 hp (model 132212) carburetor that is on a 20 year old log splitter. I disassembled the carb, cleaned it, and put in a new kit. Runs great, the only problem is the doggone thing idles wide open. My question is, what causes the throttle plate to close during idling? The throttle plate is rotated in the open position, both before starting, and after starting. I can manually close it, and the engine runs fine at lower rpm. But take my hand off of it, and wide open. There is a chance I got the linkages and the spring messed up, but do not think so. Does the governor cause the throttle plate to rotate in the closed position after starting the engine up? Or is there a missing spring that forces the throttle plate in the closed position during idling? Any help would be greatly appreciated. I do not have too much experience in working with small engine carbs.

The long linkage from the governor arm should be connected to the throttle, and the governor should move this in order to regulate engine rpm, depending on the throttle control setting. Does movement of the governor arm cause opening/closing of the throttle?

Yes, manual movement of the governor arm, or rotating the governor pin the arm is attached to, will control the throttle position. The problem seems to be there is no "springback", or motion to close the throttle when at idle. Could there be a broken, or missing spring on the governor that is supposed to close the throttle at idle? thanks

did you remove the governor arm from the gov. shaft? if so then the arm is out of adjustment. there is a tensioning bolt on the bottom of the arm that when loosened will allow adjustment of the governor. but if you did not take this off or loosen it prior to, then it is prob. ok and you just have your gov.spring in the wrong hole or the rod in the wrong hole. when the engine is not running and with the throttle wide open there should be spring tension holding the throttle butterfly wide open, when in idle position it should have no spring tension and move easily to the idle position. the governor defaults to the idle position and the spring pulls it away from the idle position opposing the governor and increasing the speed.

yea, in the process of removing the gas tank I disconnected the governor from the linkage. During re-assembly, I have tried rotating the gov shaft in both extremes, and tightening the tension bolt. In both cases, the governor seems to have no effect in closing the throttle at idle. The problem seems to be the governor does not default the throttle to idle when I have the control (lever) set to idle. However, if I slide the control lever to high (run), the spring you describe does provide more force to the throttle and keeps it open, this part of the mechanism seems to be working properly. The spring plays no role with the throttle in the closed, or idle position. Don't know if this helps, but I'm guessing the governor should be providing some force or tension to keep the throttle closed during idle but is not doing it.

I would try adjusting the governor again using the following procedure.

Locate the governor shaft where it comes out of the engine block. Loosen the arm that is attached to the shaft. Hold the throttle on the carburetor to the wide open position and note which direction the arm attached to the governor shaft moves. While holding the throttle wide open rotate the governor shaft in the same direction it would turn to open the throttle, turn it until it stops. Tighten the arm back down to the governor shaft. Thats the procedure for making the static adjustment on any internal governor, horizontal or vertical.

If the governor is working this should bring the engine back to idle when there is not tension from the governor spring.

Good Luck.

Thanks for all the comments. I'll retry adjusting the governor, but I'm pretty certain I tried this already. Based on the comments, I'm becoming more concerned the governor is not working properly. I ended up drilling and tapping a hole in the throttle plate and locking it down to the carburetor with a screw in a fixed position that allowed the engine to run at about the correct running speed. Of course, I lost the ability to control the RPM, but it's not racing out of control like it was before. Seemed to work, I successfully went thru a full tank of gas splitting firewood and the engine ran fine. If there are any other troubleshoot options, I'm certainly willing to listen. Thanks again for the advice.

It's possible that the governor is not working, resetting the static adjustment will pretty much tell the tale as long as it's done correctly. I have had the flyweights on the governors open up beyond the spool when the engine is run over speed. If this happens, then the governor will no longer operate, but can be reset, although it does require removing the sump.

One thing I forgot to mention when adjusting the governor shaft, I noticed there seemed to be a detent or obstruction when rotating the shaft. If slightly torqued higher, then you could obtain about another 1/4 turn of rotation. This did not seem right and gave me an impression something might be damaged with the governor. I also attempted to make an adjustment with the engine running, and noticed if I turned the shaft in one direction (CCW I believe), I encountered some serious vibrations, as if something within the engine was impacting the shaft at high rpm. Not sure if this provides further evidence of a damaged governor (shaft) or not.
thanks.

Oh man...do not try to adjust the governor with the engine running....